Watermelon can raise blood sugar. Watermelon tastes sweet, but its sugar content is not very high, compared to apples, bananas, mangoes, kiwis and other fruits belong to the low-sugar food, 100 grams of watermelon flesh contains 6.8 grams of sugar, and its main sugar is fructose, fructose is 1.7 times sweeter than glucose. Although the sugar content of watermelon is low, but its glycemic index is high, about 73, belongs to the high glycemic index food, will have an impact on blood glucose, especially diabetic patients with poor blood glucose control, it is not recommended to consume watermelon, for diabetic patients with good glycemic control can be consumed moderately, and pay attention to monitor the changes in blood glucose. Diabetic patients should go to the endocrinology department regularly, under the guidance of the doctor reasonable diet and regular adjustment of sugar-lowering program.